TOPSHOT - A photo taken on September 28 shows the forested area near Moscow known as Kommunarka where historians belive Stalin's NKVD secret police killed and burried more than 6000 people in 1937-41. - A team of Russian historians and archaeologists have used a Nazi bomber pilot's photograph to help them pinpoint the location of mass graves in Moscow containing the remains of thousands shot by Stalin's secret police. Historians believe at least 6,609 people were shot and thrown into mass graves in Kommunarka between 1937 and 1941. The gated forested area was once used by NKVD chief Genrikh Yagoda, who had a holiday cottage there. (Photo by Andrei BORODULIN / AFP)